<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>math</title>
		<script>
			var a=new Array(5);
			a[0]="dog";
			a[1]="pig";
			a[2]="cow";
			a[3]="sheep";
			a[4]="goat";
			var index=parseInt(Math.random()*a.length);
			alert(index);
			alert(Math.pow(4,6));
			alert(Math.sqrt(9));
			alert(Math.round(35.777));
		</script>
	</head>
	<body>
	</body>
</html>